During fresh vegetable and fruit processing, the processor must contend with three natural problems: discoloration which destroys a esthetic appeal (notably, lettuce wilting; fruits and potatoes browning); oxidation, which has an effect on taste; and microbiological growth, which can result in the aforementioned effects as well as the production of toxins. Once the peel or outer layer has been removed from a fruit or vegetable, all of the aforementioned problems begin to occur. To illustrate, it can be readily observed that fresh peeled potatoes will begin to brown (discolor) within ten minutes after the removal of the skin. Thus, for all practical commercial purposes, the shelf life of fresh peeled potatoes is less than ten minutes.
For the past 100 years, it is been common to employ sulfiting agents such as sodium bisulfite to retard the enzymatic and oxidizing processes. Control over micro-organisms and microbiological growth has been attained through the use of other preservatives or refrigeration, radiation, and other methods directed toward antibiosis.
Relative to the prevention of the non-microbiological processes, sulfiting agents have proven to be quite successful. However, this success has, in several instances, been attained at great cost. It is been found that a small part of the population may encounter serious reactions to products that have been processed using sulfiting agents. In some cases, this reaction has caused the death of consumers. Hightened consumer awareness of the danger of sulfites has lead to numerous complaints to the Food and Drug Administration (FDA) and is best illustrated by current writings found in both the media and semi-professional journals.
In TIME, Oct. 14, 1985, Anastasia Toufexis wrote: "An additional 850 people have reported allergy-like reactions to the chemicals, 80% after eating sulfite-laced fruits and vegetables at salad bars and restaurants. This Fall, after almost three years of study, the Food and Drug Administration will impose a ban on the use of six sulfite preservatives in fresh produce." And, further in the article she writes: "To safeguard the public, the Center for Science is urging an outright ban on all use of sulfites. But others note that very few ill effects are documented from sulfites in packaged foods and that there is no substitute for them in making wine. Of the 12 sulfite-associated deaths, only one was caused by wine, one by beer and one by hash brown potatoes. The rest were all linked to fresh fruits or vegetables." And, ". . . and they should not go to salad bars, at least until the ban goes into effect (emphasis added)".
Less than two months later, reporting for the FDA Consumer, December 1985-January 1986, in an article entitled Reacting to Sulfites, Chris Lecos, a member of FDA'S public affairs staff, stated: "Over the last three and one half years there has been extensive publicity and controversy surrounding the wide spread use of sulfiting agents in the food supply. The controversy stems from sulfites' potential for triggering moderate to severe adverse reactions, including death, in certain sulfite-sensitive individuals. (However, sulfites are not considered hazards to the general population)." Writer Lecos further informs us that "Sulfiting agents are primarily used to reduce or prevent spoilage and discoloration during the preparation, storage and distribution of many foods. They are used in many packaged potato products to preserve the vegetable's white appearance." And, ". . . FASEB recommended regulatory action by FDA on the use of sulfites on fresh fruits and vegetables and pre-cut potatoes." Finally, the public is advised that "FDA is not expected to take final action on the two proposals until 1986. Both proposals triggered a substantial response from industry, consumer groups and others, and neither will go into effect until after FDA reviews the comments received and publishes a final regulation. FDA also is considering a regulation dealing with a widespread use of sulfites in processed potato products (applicant emphasis added). Even with the adoption of the two proposed regulations, sulfite-sensitive consumers would still have to be alert to the possible presence of sulfites in the foods they eat at home or in restaurants. Food served in restaurants generally are not packaged and therefore are not labeled. Most packaged potato products (applicant emphasis added) used by restaurants, for example, are treated with sulfites, as are other canned products used in cooking. Generally, foods and beverages that sulfite-sensitive consumers should be alert to are salads, potatoes (applicant emphasis added), seafood, cooked vegetable dishes, wine, beer, and bakery products."
Applicant-inventors are particularly concerned with the preservation of fresh peeled whole potatoes. In a recent New York State Industries for the Handicapped (NYSIH)-funded project report, produced by the Food Research Institute (University of Wisconsin-Madison) and dated Sept. 25, 1985, the Executive Director for NYSIH was advised that, relative to the processing of peeled potatoes "Sulfite solutions were the only effective dipping solutions to prevent browning."
The inventors, paying heed to the prospective FDA ban of sulfites, have, for the past few years, been experimenting with possible alternatives to the use of sulfites. During the preparation of whole peeled potatoes, it is necessary to impede the discoloration process immediately after peeling. It has been determined that an immediate dip in a discoloration retarding solution, whether using sulfites or alternatives, is necessary. A 20-30 minute period is allowed for finished trimming of the potatoes to remove parts which are considered to be unappetizing or adulterated. Immediately upon termination of the trimming period, the potatoes are subjected to a second dip and, thereafter, removed for packaging and refrigeration. With this general method, sulfiting of fresh whole peeled potatoes results in satisfactory shelf lives (at 8.degree. C.) for up to ten days. It was therefore our experimental goal, should a sulfite substitute be found, to develop a composition and process that would equal or exceed the sulfite-produced shelf life.
Thus it is the principal object of this invention to provide a new and improved compound or combination of compounds which may be used as an alternative to the use of sulfites as inhibitors of discoloration in foods.
Another object of this invention is to provide the aforementioned compounds in a form readily applicable to fresh peeled vegetables, leafy vegetables and fresh peeled fruits.
It is yet another object of this invention to develop and provide a method of application of the sulfite alternative to fresh fruits and vegetables.
Objects and advantages of this invention are set forth in part herein and in part will be obvious through practice with the invention.